Curable liquid resin composition

ABSTRACT

To provide a radiation-sensitive curable liquid resin composition having excellent applicability and capable of producing a film excelling in hardness, scratch resistance, adhesion, transparency, and appearance of the surface of the film. 
     A curable liquid resin composition comprising: (A) particles prepared by bonding at least one oxide of an element selected from the group consisting of silicon, aluminum, zirconium, titanium, zinc, germanium, indium, tin, antimony, and cerium to a specific organic compound which comprises a polymerizable unsaturated group and a group shown by —X—C(═Y)—NH— (wherein X is NH, O, or S, and Y is O or S), and preferably a silanol group, (B) a compound having two or more polymerizable unsaturated groups in the molecule, (C) a specific alkylene glycol organic solvent, and preferably (D) a polymerization initiator.

CROSS REFERENCE TO RELATED APPLICATION

This application is the National Phase of International ApplicationPCT/NL02/00623 filed Sep. 26, 2002 which designated the U.S., and thatInternational Application was published under PCT Article 21(2) inEnglish.

DETAILED DESCRIPTION OF THE INVENTION

1. Field of the Invention

The present invention relates to a curable liquid resin compositionexhibiting film formability. The present invention also relates to acurable liquid resin composition capable of being cured by applicationof heat or radiation. More particularly, the present invention relatesto a resin composition exhibiting excellent applicability and filmformability, and capable of forming a film excelling in hardness,scratch resistance, adhesion, transparency, and appearance on thesurface of various types of substrates such as polyester(polyethyleneterephthalate and polybuthyleneterephthalate), plastics(polycarbonate, triacetyl cellulose, polymethylmethacrylate,polystyrene, polyolefin, epoxy, melamine, ABS resin, AS resin,norbornene resins, metals, wood, paper, glass, and slates. The curableliquid resin composition of the present invention is suitably used as aprotective coating material to prevent scratches or stains on plasticoptical parts, optical disks such as CD and DVD, touch panels, film-typeliquid crystal elements, plastic containers, flooring materials, wallmaterials, and artificial marbles as interior architectural finish, andthe like. The curable liquid resin composition is used as an adhesiveand sealing material for substrates and a vehicle material for printingink.

2. Prior Art

In recent years, a resin composition exhibiting excellent applicabilityand capable of forming a film excelling in hardness, scratch resistance,adhesion, transparency, and appearance is desired as a protectivecoating material to prevent scratches or stains on the surface ofvarious substrates. Various types of materials using colloidal silica ascomponent particles have been proposed aiming to improve scratchresistance. For example, U.S. Pat. No. 3,451,838 and U.S. Pat. No.2,404,357 disclose compositions comprising a hydrolyzate of alkoxysilaneand colloidal silica as major components to be used as a heat-curablecoating material. Japanese Patent Publication No. 21815/1987 disclosesuse of a composition containing an acrylate and colloidal silicaparticles of which the surface is modified by methacryloxysilane as aphotocurable coating material. The feature of these coating materials isto improve the performance of the coating materials by treating thesurface of silica particles with a specific organic silane or treatingunder specific conditions. However, these coating materials do notnecessarily satisfy excellent applicability as a curable liquid resincomposition and provide excellent hardness, scratch resistance,adhesion, transparency, and appearance as a cured film.

Problems to be Solved by the Invention

The present invention has been achieved in view of the above problems.An object of the present invention is to provide a curable liquid resincomposition exhibiting excellent applicability and capable of forming afilm excelling in hardness, scratch resistance, adhesion, andtransparency on the surface of various types of substrates.

Means for Solving the Problems

As a result of extensive studies to achieve the above object, thepresent inventors have found that all the above characteristics can besatisfied by a curable liquid resin composition comprising (A)crosslinkable particles prepared by bonding oxide particles of aspecific element to an organic compound having a specific group, (B) acompound having two or more polymerizable unsaturated groups in themolecule, and (C) an organic solvent having a specific structure. Thisfinding has led to the completion of the present invention.Specifically, the present invention provides a curable liquid resincomposition given below.

-   [1] A curable liquid resin composition comprising: (A) crosslinkable    particles prepared by bonding (A1) oxide particles of at least one    element selected from the group consisting of silicon, aluminum,    zirconium, titanium, zinc, germanium, indium, tin, antimony, and    cerium to (A2) a specific organic compound which comprises (A21) a    polymerizable unsaturated group and (A22) a group shown by the    following formula (1), (B) a compound having (B1) two or more    polymerizable unsaturated groups in the molecule, and (C) at least    one organic solvent selected from compounds shown by the following    formula (2);    —X—C(═Y)—NH—  (1)    wherein X represents NH, O (oxygen atom), or S (sulfur atom), and Y    represents O or S;    R²—(O—R¹)_(n)—O—R³  (2)    wherein R¹ represents a divalent organic group selected from    —CH₂CH₂—, —CH₂CH₂CH₂—, and —CH(CH₃)CH₂—, R² and R³ represent a    hydrogen atom or a monovalent organic group selected from an alkyl    group having 1–4 carbon atoms and CH₃CO—, and n is 1 or 2.-   [2] The curable liquid resin composition according to the above [1],    wherein the specific organic compound (A2) comprises a group shown    by —O—C(═O)—NH— and at least one of the groups shown by —O—C(═S)—NH—    and —S—C(═O)—NH—.-   [3] The curable liquid resin composition according to the above [1]    or [2], wherein the specific organic compound (A2) is a compound    having (A23) a silanol group or (A24) a group which forms a silanol    group by hydrolysis.-   [4] The curable liquid resin composition according to any one of the    above [1] to [3], further comprising (D) a polymerization initiator    in addition to the components (A), (B), and (C).-   [5] The curable liquid resin composition according to any one of the    above [1] to [4], wherein the polymerization initiator (D) is (D1) a    photoinitiator which comprises at least either an arylketone having    a 1-hydroxycyclohexyl group or an arylketone having an N-morpholino    group.

In the present invention, “radiation” includes infrared rays, visiblerays, ultraviolet rays, deep ultraviolet rays, X-rays, electron beams,α-rays, β-rays, γ-rays, and the like.

PREFERRED EMBODIMENT OF THE INVENTION

A resin composition of the present invention comprises (A) crosslinkableparticles prepared by bonding oxide particles of a specific element toan organic compound having a specific group, (B) a compound having twoor more polymerizable unsaturated groups in the molecule, (C) an organicsolvent having a specific structure, and, optionally, (D) apolymerization initiator.

Each component of the curable liquid resin composition of the presentinvention is described below in detail.

1. Crosslinkable Particles (A)

The crosslinkable particles (A) used in the present invention areproduced by bonding (A1) oxide particles of at least one elementselected from the group consisting of silicon, aluminum, zirconium,titanium, zinc, germanium, indium, tin, antimony, and cerium, to (A2) aspecific organic compound having (A21) a polymerizable unsaturated groupand (A22) a group shown by the above formula (1).

(1) Oxide Particles (A1)

The oxide particles used in the present invention are particles of anoxide of at least one element selected from the group consisting ofsilicon, aluminum, zirconium, titanium, zinc, germanium, indium, tin,antimony, and cerium from the viewpoint of colorlessness of a cured filmof the resulting curable liquid resin composition.

As examples of these oxides, silica, alumina, zirconia, titania, zincoxide, germanium oxide, indium oxide, tin oxide, indium-tin oxide (ITO),antimony oxide, and cerium oxide can be given. Of these, silica,alumina, zirconia, and antimony oxide are preferable from the viewpointof high hardness. These oxide particles may be used either individuallyor in combination of two or more. The oxide particles of these elementsare preferably in the form of powder or a solvent dispersion sol. If theoxide particles are in the form of a solvent dispersion sol, an organicsolvent is preferably used as a dispersion medium in view of miscibilityand dispersibility in other components.

As examples of the organic solvent, alcohols such as methanol, ethanol,isopropanol, butanol, and octanol; ketones such as acetone, methyl ethylketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethylacetate, butyl acetate, ethyl lactate, and γ-butyrolactone; ethers suchas ethylene glycol monomethyl ether and diethylene glycol monobutylether; aromatic hydrocarbons such as benzene, toluene, and xylene; andamides such as dimethylformamide, dimethylacetamide, andN-methylpyrrolidone can be given. Of these, methanol, isopropanol,butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate,butyl acetate, toluene, and xylene are preferable.

The number average particle diameter of the oxide particles ispreferably from 0.001 to 2 μm, still more preferably from 0.001 to 0.2μm, and particularly preferably from 0.001 μm to 0.1 μm. If the numberaverage particle diameter is more than 2 μm, transparency of theresulting cured product may be decreased or the surface conditions ofthe film may be impaired. Various surfactants or amines may be added tothe solvent in order to improve dispersibility of the particles.

As examples of commercially available products of silicon oxideparticles (silica particles, for example), colloidal silica such asMethanol Silica Sol, IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP,ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL (manufactured byNissan Chemical Industries, Ltd.), and the like can be given. Asexamples of commercially available products of powdered silica, AEROSIL130, AEROSIL 300, AEROSIL 380, AEROSIL TT600, and AEROSIL OX50(manufactured by Japan Aerosil Co., Ltd.), Sildex H31, H32, H51, H52,H121, H122 (manufactured by Asahi Glass Co., Ltd.), E220A, E220(manufactured by Nippon Silica Industrial Co., Ltd.), SYLYSIA 470(manufactured by Fuji Silysia Chemical Co., Ltd.), SG Flake(manufactured by Nippon Sheet Glass Co., Ltd.), and the like can begiven.

As examples of other commercially available products, aqueous dispersionof alumina such as Alumina Sol-100, 200, 520 (manufactured by NissanChemical Industries, Ltd.); isopropanol dispersion of alumina such asAS-150I (manufactured by Sumitomo Osaka Cement Co., Ltd.); toluenedispersion of alumina such as AS-150T (manufactured by Sumitomo OsakaCement Co., Ltd.); aqueous dispersion of zinc antimonate powder such asCelnax (manufactured by Nissan Chemical Industries, Ltd.); powder andsolvent dispersion of alumina, titanium oxide, tin oxide, indium oxide,zinc oxide such as Nano Tek (manufactured by C.I. Kasei Co., Ltd.);aqueous dispersion sol of antimony doped tin oxide such as SN-100D(manufactured by Ishihara Sangyo Kaisha, Ltd.); ITO powder such as aproduct manufactured by Mitsubishi Material Co., Ltd.; aqueousdispersion of cerium oxide such as Needral (manufactured by TakiChemical Co., Ltd.), and the like can be given.

The shape of the oxide particles is globular, hollow, porous, rod,plate, fibrous, or amorphous. Of these, a globular shape is preferable.The specific surface area of the oxide particles (measured by a BETmethod using nitrogen) is preferably from 10 to 1000 m²/g, and stillmore preferably 100 to 500 m²/g. The oxide particles may be used in theform of dry powder or a dispersion in water or an organic solvent. Forexample, a dispersion liquid of fine oxide particles known in the art asa solvent dispersion sol of the above oxides may be used. Use of asolvent dispersion sol of the oxide is particularly preferable if hightransparency is necessary for the cured product.

(2) Specific Organic Compound (A2)

The specific organic compound used in the present invention has thepolymerizable unsaturated group (A21) and the group (A22) shown by theabove formula (1) in the molecule. The specific organic compoundpreferably has a silanol group (A23) or a group (A24) which forms asilanol group by hydrolysis in the molecule.

The specific organic compound (A2) bonds to the oxide particles (A1) ata site other than the polymerizable unsaturated group (A21), andpreferably at the silanol group (A23) to form the crosslinkableparticles (A). The polymerizable unsaturated group (A21) in theparticles provide crosslinking properties to the particles.

(2–1) Polymerizable Unsaturated Group (A21)

There are no specific limitations to the polymerizable unsaturated groupincluded in the specific organic compound. An acryloyl group,methacryloyl group, vinyl group, propenyl group, butadienyl group,styryl group, ethynyl group, cinnamoyl group, maleate group, andacrylamide group can be given as suitable examples.

(2-2) Group (A22) Shown by Formula (1)

The group [—X—C(═Y)—NH—] shown by the formula (1) included in thespecific organic compound (A2) is one of [—O—C(═O)—NH—], [—O—C(═S)—NH—],[—S—C(═O)—NH—], [—NH—C(═O)—NH—], [—NH—C(═S)—NH—], and [—S—C(═S)—NH—].These groups may be used either individually or in combination of two ormore. It is preferable to use the group [—O—C(═O)—NH—] and at least oneof the groups [—O—C(═S)—NH—] and [—S—C(═O)—NH—] in combination from theviewpoint of thermal stability. It is considered that the group[—X—C(═Y)—NH—] shown by the formula (1) produces a moderate cohesiveforce between the molecules by a hydrogen bond and provides theresulting cured product with characteristics such as superior mechanicalstrength, adhesion to substrates, and heat resistance.

(2–3) Silanol Group (A23) or Group (A24) Which forms Silanol Group byHydrolysis

The specific organic compound (A2) is preferably a compound having thesilanol group (A23) (hereinafter may be referred to as “silanolgroup-containing compound”) or a compound having the group (A24) whichforms a silanol group by hydrolysis (hereinafter may be referred to as“silanol group-forming compound”) in the molecule. As examples of thesilanol group-forming compound, a compound having an alkoxy group,aryloxy group, acetoxy group, amino group, halogen group, or the like onthe silicon atom can be given. Of these, compounds including an alkoxygroup or aryloxy group on the silicon atom, specifically, an alkoxysilylgroup-containing compound or an aryloxysilyl group-containing compoundare preferable.

The silanol group-forming site of the specific organic compound having asilanol group or the group which forms a silanol group is a structuralunit which bonds to the oxide particles by condensation or condensationoccurring after hydrolysis.

The compound shown by the following formula (3) can be given as apreferable example of (2-4) the specific organic compound (A2):(R⁴O)mR⁵ _(3-m)Si—R⁶—S—CO—NH—R⁷—NH—CO—O—R⁸-(Z)_(n)  (3)wherein R⁴ and R⁵ individually represent a hydrogen atom or an alkylgroup or an aryl group having 1–8 carbon atoms such as a methyl group,ethyl group, propyl group, butyl group, octyl group, phenyl group, andxylyl group, and m is 1, 2, or 3.

As examples of the group [(R⁴O)_(m)R⁵ _(3-m)Si—] in the above formula, atrimethoxysilyl group, triethoxysilyl group, triphenoxysilyl group,methyldimethoxysilyl group, dimethylmethoxysilyl group, and the like canbe given. Of these, a trimethoxysilyl group and a triethoxysilyl groupare preferable.

R⁶ is a divalent organic group having an aliphatic structure or anaromatic structure having 1–12 carbon atoms and may include a linear,branched, or cyclic structure. As examples of such an organic group,methylene, ethylene, propylene, butylene, hexamethylene, cyclohexylene,phenylene, xylylene, dodecamethylene, and the like can be given. Ofthese, methylene, propylene, cyclohexylene, phenylene, and the like arepreferable.

R⁷ is a divalent organic group selected from divalent organic groupshaving a molecular weight of 14–10,000, and preferably 76–500. Asexamples of such divalent organic groups, a linear polyalkylene groupsuch as hexamethylene, octamethylene, and dodecamethylene; an alicyclicor polycyclic divalent organic group such as cyclohexylene andnorbornylene; a divalent aromatic group such as phenylene, naphthylene,biphenylene, and polyphenylene; and an alkyl group or aryl groupsubstitution product of these groups can be given. These divalentorganic groups may include a group having an element other than a carbonatom and a hydrogen atom. These divalent organic groups may include apolyether bond, polyester bond, polyamide bond, polycarbonate bond, andthe group shown by the above formula (1).

R⁸ is an organic group with a valence of (n+1) and preferably selectedfrom linear, branched, or cyclic, saturated or unsaturated hydrocarbongroups.

Z represents a monovalent organic group having a polymerizableunsaturated group in the molecule. As examples of such a monovalentorganic group, an acryloyl(oxy) group, methacryloyl(oxy) group,vinyl(oxy) group, propenyl(oxy) group, butadienyl(oxy) group,styryl(oxy) group, ethynyl(oxy) group, cinnamoyl(oxy) group, maleategroup, acrylamide group, methacrylamide group, and the like can begiven. Of these, an acryloyl(oxy) group and a methacryloyl(oxy) groupare preferable. n is an integer preferably from 1 to 20, and morepreferably from 1 to 10, and particularly preferably from 1 to 5.

The specific organic compound (A2) used in the present invention may besynthesized by using a method disclosed in Japanese Patent ApplicationLaid-open No. 9-100111, for example. Specifically, the specific organiccompound (A2) may be synthesized by an addition reaction of amercaptoalkoxysilane, a polyisocyanate compound, and an active hydrogengroup-containing polymerizable unsaturated compound (method (1)). Thespecific organic compound (A2) may be synthesized by a direct reactionof a compound having an alkoxysilyl group and an isocyanate group in themolecule with an active hydrogen-containing polymerizable unsaturatedcompound (method (2)). The specific organic compound (A2) may besynthesized by an addition reaction of a compound having a polymerizableunsaturated group and an isocyanate group in the molecule withmercaptoalkoxysilane or aminosilane (method (3)).

The compound shown by the above formula (3) is preferably synthesized byusing the method (a). In more detail, the compound shown by the formula(3) is synthesized by using a method (a) which comprises forming anintermediate compound having an alkoxysilyl group, a group[—S—C(═O)NH—], and an isocyanate group in the molecule by reactingmercaptoalkoxysilane with a polyisocyanate compound, and reacting ahydroxyl group-containing polymerizable unsaturated compound with theisocyanate group remaining in the intermediate compound, thereby causingthe unsaturated compound to bond via the group [—S—C(═O)NH—], a method(b) which comprises forming an intermediate compound having apolymerizable unsaturated group, a group [—O—C(═O)—NH—], and anisocyanate group in the molecule by reacting a polyisocyanate compoundwith a hydroxyl group-containing polymerizable unsaturated compound, andreacting the intermediate compound with mercaptoalkoxysilane, therebycausing mercaptoalkoxysilane to bond via the group [—S—C(═O)—NH—], orthe like. Of these two methods, the method (a) is preferred because adecrease in the polymerizable unsaturated group due to the Michaeladdition reaction does not occur.

As examples of alkoxysilane capable of forming the group [—S—C(═O)—NH—]by the reaction with an isocyanate group in the synthesis of thecompound shown by the above formula (3), compounds having at least onealkoxysilyl group and at least one mercapto group in the molecule can begiven. As examples of mercaptoalkoxysilane,mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane,mercaptopropylmethyldiethoxysilane, mercaptopropyldimethoxymethylsilane,mercaptopropylmethoxydimethylsilane, mercaptopropyltriphenoxysilane,mercaptopropyltributoxysilane, and the like can be given. Of these,mercaptopropyltrimethoxysilane and mercaptopropyltriethoxysilane arepreferable. An addition compound of an amino-substituted alkoxysilaneand an epoxy group-substituted mercaptan or an addition compound ofepoxysilane and α,ω-dimercapto compound may also be used.

The polyisocyanate compound used for synthesizing the specific organiccompound may be selected from polyisocyanate compounds consisting of alinear saturated hydrocarbon, cyclic saturated hydrocarbon, or aromatichydrocarbon.

As examples of such a polyisocyanate compound, 2,4-tolylenediisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate,1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylenediisocyanate, p-phenylene diisocyanate,3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethanediisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylenediisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate,methylenebis(4-cyclohexylisocyanate), 2,2,4-trimethylhexamethylenediisocyanate, bis(2-isocyanatethyl)fumarate, 6-isopropyl-1,3-phenyldiisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate,hydrogenated diphenylmethane diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, tetramethylxylylene diisocyanate, 2,5(or6)-bis(isocyanatemethyl)-bicyclo[2.2.1]heptane, and the like can begiven. Of these, 2,4-tolylene diisocyanate, isophorone diisocyanate,xylylene diisocyanate, methylenebis(4-cyclohexylisocyanate),1,3-bis(isocyanatemethyl)cyclohexane, and the like are preferable. Thesecompounds may be used either individually or in combination of two ormore.

As examples of the active hydrogen-containing polymerizable unsaturatedcompound which can be bonded via the group [—O—C(═O)—NH—] by theaddition reaction with the polyisocyanate compound used in the synthesisof the specific organic compound, compounds having at least one activehydrogen atom which can form the group [—O—C(═O)—NH—] by the additionreaction with an isocyanate group and at least one polymerizableunsaturated group in the molecule can be given.

As examples of the active hydrogen-containing polymerizable unsaturatedcompound, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,2-hydroxybutyl(meth)acrylate, 2-hydroxy-3-phenyloxypropyl(meth)acrylate,1,4-butanediol mono(meth)acrylate, 2-hydroxyalkyl(meth)acryloylphosphate, 4-hydroxycyclohexyl(meth)acrylate, 1,6-hexanediolmono(meth)acrylate, neopentyl glycol mono(meth)acrylate,trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate,pentaerythritol tri(meth)acrylate, dipentaerythritolpenta(meth)acrylate, and the like can be given. A compound obtained bythe addition reaction of a glycidyl group-containing compound such asalkyl glycidyl ether, allyl glycidyl ether, or glycidyl(meth)acrylateand (meth)acrylic acid may also be used. Of these compounds,2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,pentaerythritol tri(meth)acrylate, and the like are preferable.

These compounds may be used either individually or in combination of twoor more.

(3) Preparation of Crosslinkable Particles (A)

There are no specific limitations to the method for preparing thecrosslinkable particles (A) used in the present invention. For example,a method of reacting the oxide particles with the specific organiccompound can be given. The oxide particles contain moisture on thesurface of the particles as adsorbed water under usual storageconditions. It is estimated that a component which reacts with thesilanol group-forming compound such as a hydroxide, hydrate, or the likeis present at least on the surface of the oxide particles. Therefore,the crosslinkable particles (A) can be prepared by mixing the silanolgroup-forming compound and oxide particles and heating the mixture whilestirring. The reaction is preferably carried out in the presence ofwater in order to efficiently cause the silanol group-forming site ofthe specific organic compound to bond to the oxide particles. However,water need not be present if the specific organic compound has a silanolgroup. Therefore, the crosslinkable particles (A) may be prepared by amethod including at least an operation of mixing the oxide particles andthe specific organic compound.

The method for preparing the crosslinkable particles (A) is describedbelow in detail.

The amount of the specific organic compound bonded to the oxideparticles in the crosslinkable particles (A) is preferably 0.01 wt % ormore, still more preferably 0.1 wt % or more, and particularlypreferably 1 wt % or more for 100 wt % of the crosslinkable particles(A) (oxide particles and specific organic compound in total). If theamount of the specific organic compound bonded to the oxide particles isless than 0.01 wt %, dispersibility of the crosslinkable particles (A)in the composition may be insufficient, whereby the resulting curedproduct has insufficient transparency and scratch resistance. Thecontent of the oxide particles in the raw materials in the preparationof the crosslinkable particles (A) is preferably 5–99 wt %, and morepreferably 10–98 wt %.

The method for preparing the crosslinkable particles (A) is describedbelow in more detail taking the alkoxysilyl group-containing compound(alkoxysilane compound) shown by the above formula (3) as an example ofthe silanol group-forming compound.

The amount of water consumed during hydrolysis of the alkoxysilanecompound in the preparation of the crosslinkable particles (A) isdetermined so that at least one alkoxy group on the silicon atom in themolecule is hydrolyzed. The amount of water added or present duringhydrolysis is preferably ⅓ or more of the number of moles of the totalalkoxy groups on the silicon atom, and still more preferably from ½ to 3times or less of the number of moles of the total alkoxy groups. Aproduct obtained by mixing the alkoxysilane compound and the oxideparticles under conditions in which water is completely absent is aproduct in which the alkoxysilane compound is physically adsorbed on thesurface of the oxide particles. A cured product of the compositioncontaining such crosslinkable particles (A) exhibits only low hardnessand scratch resistance.

In the preparation of crosslinkable particles (A), a method ofseparately hydrolyzing the alkoxysilane compound, mixing the hydrolyzateand powder of the oxide particles or a solvent dispersion sol of theoxide particles, and heating the mixture while stirring; a method ofhydrolyzing the alkoxysilane compound in the presence of the oxideparticles; a method of treating the surface of the oxide particles inthe presence of the polymerization initiator (D), or the like may beselectively used. Of these, the method of hydrolyzing the alkoxysilanecompound in the presence of the oxide particles is preferable. Thecrosslinkable particles (A) are prepared at a temperature preferablyfrom 0 to 150° C., and still more preferably from 20 to 100° C. Thetreating time is usually from five minutes to 24 hours.

In the case of using oxide particles in the form of powder in thepreparation of the crosslinkable particles (A), an organic solvent maybe added in order to ensure a smooth and homogeneous reaction of theoxide particles and the alkoxysilane compound. A solvent the same asused as the dispersion medium of the solvent dispersion sol of the oxideparticles may be used as such an organic solvent. There are no specificlimitations to the amount of these solvents insofar as a smooth andhomogeneous reaction is ensured.

In the case of using a solvent dispersion sol as the raw material forthe crosslinkable particles (A), the crosslinkable particles (A) may beprepared by merely mixing the solvent dispersion sol and the specificorganic compound. An organic solvent miscible with water may be added tosecure homogeneity at an initial stage of the reaction and promote asmooth reaction.

An acid, salt, or base may be added as a catalyst in the preparation ofthe crosslinkable particles (A) in order to promote the reaction. Asexamples of the acid, inorganic acids such as hydrochloric acid, nitricacid, sulfuric acid, and phosphoric acid, organic acids such asmethanesulfonic acid, toluenesulfonic acid, phthalic acid, malonic acid,formic acid, acetic acid, and oxalic acid, unsaturated organic acidssuch as methacrylic acid, acrylic acid, and itaconic acid, and the likecan be given. As examples of the salt, ammonium salts such astetramethylammonium chloride and tetrabutylammonium chloride, and thelike can be given. As examples of the base, aqueous ammonia, primary,secondary, or tertiary aliphatic amines such as diethylamine,triethylamine, dibutylamine, and cyclohexylamine, aromatic amines suchas pyridine; sodium hydroxide, potassium hydroxide, quaternary ammoniumhydroxides such as tetramethylammonium hydroxide, tetrabutylammoniumhydroxide, and the like can be given.

Of these, organic acids and unsaturated organic acids are preferable asthe acid. As the base, tertiary amines and quaternary ammoniumhydroxides are preferable. The amount of the acid, salt, or base ispreferably from 0.001 to 1.0 part by weight, and still more preferablyfrom 0.01 to 0.1 part by weight for 100 parts by weight of thealkoxysilane compound.

A dehydrating agent is preferably added in order to promote thereaction. As the dehydrating agent, inorganic compounds such as zeolite,anhydrous silica, and anhydrous alumina, and organic compounds such asmethyl orthoformate, ethyl orthoformate, tetraethoxymethane, andtetrabutoxymethane may be used. Of these, organic compounds arepreferable. Use of ortho esters such as methyl orthoformate and ethylorthoformate is particular preferable.

The amount of the alkoxysilane compound bonded to the crosslinkableparticles (A) is determined as a constant value of weight loss (%) whendry powder is completely burnt in air by thermogravimetric analysis at atemperature from 110 to 800° C. in air.

The amount of crosslinkable particles (A) in the resin composition isfrom 5 to 90 wt %, and preferably from 10 to 70 wt % for 100 wt % of thecomposition (crosslinkable particles (A) and compound (B) in total). Ifthe amount is less than 5 wt %, hardness of the resulting cured productmay be insufficient. If the amount exceeds 90 wt %, the composition maynot be cured (film may not be formed). The amount of the crosslinkableparticles (A) used herein refers to the solid content and does notinclude the amount of the solvent in the case where the crosslinkableparticles (A) are used in the form of a solvent dispersion sol.

2. Compound (B) Having Two or More Polymerizable Unsaturated Groups inthe Molecule (Hereinafter May Be Referred to as “Compound (B)”)

The compound (B) is suitably used to increase film-formability of thecurable liquid resin composition of the present invention. There are nospecific limitations to the compound (B) insofar as the compound has twoor more polymerizable unsaturated groups. As examples of the compound(B), (meth)acrylates and vinyl compounds can be given. Of these,(meth)acrylates are preferable.

Specific examples of the compound (B) used in the present invention aregiven below.

As examples of (meth)acrylates, trimethylolpropane tri(meth)acrylate,ditrimethylolpropane tetra(meth)acrylate, pentaerythritoltri(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol penta(meth)acrylate, dipentaerythritolhexa(meth)acrylate, glycerol tri(meth)acrylate,tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethylene glycoldi(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate, dipropylene glycol di(meth)acrylate,bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, poly(meth)acrylates ofethylene oxide or propylene oxide addition product of starting alcoholsof these (meth)acrylates, oligoester(meth)acrylates,oligoether(meth)acrylates, oligourethane(meth)acrylates, andoligoepoxy(meth)acrylates having two or more (meth)acryloyl groups inthe molecule, and the like can be given. Of these, dipentaerythritolhexa(meth)acrylate, dipentaerythritol penta(meth)acrylate,pentaerythritol tetra(meth)acrylate, and ditrimethylolpropanetetra(meth)acrylate are preferable.

As examples of vinyl compounds, divinylbenzene, ethylene glycol divinylether, diethylene glycol divinyl ether, triethylene glycol divinylether, and the like can be given.

As examples of commercially available products of the compound (B),Aronix M-400, M-408, M-450, M-305, M-309, M-310, M-315, M-320, M-350,M-360, M-208, M-210, M-215, M-220, M-225, M-233, M-240, M-245, M-260,M-270, M-1100, M-1200, M-1210, M-1310, M-1600, M-221, M-203, TO-924,TO-1270, TO-1231, TO-595, TO-756, TO-1231, TO-1343, TO-902, TO-904,TO-905, TO-1330 (manufactured by Toagosei Co., Ltd.); KAYARAD D-310,D-330, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN-2475,SR-295, SR-355, SR-399E, SR-494, SR-9041, SR-368, SR-415, SR-444,SR-454, SR-492, SR-499, SR-502, SR-9020, SR-9035, SR-111, SR-212,SR-213, SR-230, SR-259, SR-268, SR-272, SR-344, SR-349, SR-601, SR-602,SR-610, SR-9003, PET-30, T-1420, GPO-303, TC-120S, HDDA, NPGDA, TPGDA,PEG400DA, MANDA, HX-220, HX-620, R-551, R-712, R-167, R-526, R-551,R-712, R-604, R-684, TMPTA, THE-330, TPA-320, TPA-330, KS-HDDA,KS-TPGDA, KS-TMPTA (manufactured by Nippon Kayaku Co., Ltd.); LightAcrylate PE-4A, DPE-6A, DTMP-4A (manufactured by Kyoeisha Chemical Co.,Ltd.); and the like can be given.

The amount of the compound (B) used in the present invention ispreferably from 10 to 95 wt %, and more preferably from 30 to 90 wt %for 100 wt % of the composition (crosslinkable particles (A) andcompound (B) in total). If the amount is less than 10 wt %, hardness ofthe resulting cured product may be insufficient. If the amount exceeds95 wt %, the cured product may curl to a large extent, whereby problemsmay occur after forming the film. In addition to the compound (B), acompound having one polymerizable unsaturated group in the molecule mayoptionally be used in the composition of the present invention.

3. Organic Solvent (C)

The organic solvent (C) used in the present invention is a compoundshown by the above formula (2).

As examples of such a solvent, ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, ethylene glycol monopropyl ether,ethylene glycol monobutyl ether, ethylene glycol dimethyl ether,ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethyleneglycol dibutyl ether, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, diethylene glycol monopropyl ether, diethyleneglycol monobutyl ether, diethylene glycol dimethyl ether, diethyleneglycol diethyl ether, diethylene glycol dipropyl ether, diethyleneglycol dibutyl ether, ethylene glycol methyl ether acetate, ethyleneglycol ethyl ether acetate, ethylene glycol propyl ether acetate,ethylene glycol butyl ether acetate, diethylene glycol methyl etheracetate, diethylene glycol ethyl ether acetate, diethylene glycol propylether acetate, diethylene glycol butyl ether acetate, ethylene glycoldiacetate, diethylene glycol diacetate, propylene glycol monomethylether, propylene glycol monoethyl ether, propylene glycol monopropylether, propylene glycol monobutyl ether, propylene glycol dimethylether, propylene glycol diethyl ether, propylene glycol dipropyl ether,propylene glycol dibutyl ether, dipropylene glycol monomethyl ether,diprdpylene glycol monoethyl ether, dipropylene glycol monopropyl ether,dipropylene glycol monobutyl ether, dipropylene glycol dimethyl ether,dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether,dipropylene glycol dibutyl ether, propylene glycol methyl ether acetate,propylene glycol ethyl ether acetate, propylene glycol propyl etheracetate, propylene glycol butyl ether acetate, dipropylene glycol methylether acetate, dipropylene glycol ethyl ether acetate, dipropyleneglycol propyl ether acetate, dipropylene glycol butyl ether acetate,propylene glycol diacetate, dipropylene glycol diacetate,3-methoxy-1-propanol, 3-ethoxy-1-propanol, 3-propoxy-1-propanol, and thelike can be given. Of these, ethylene glycol monopropyl ether, ethyleneglycol monobutyl ether, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, propylene glycol monopropyl ether, propyleneglycol monobutyl ether, propylene glycol methyl ether acetate, propyleneglycol ethyl ether acetate, and propylene glycol propyl ether acetateare preferable. These compounds may be used either individually or incombination of two or more.

The amount of the organic solvent (C) used in the curable liquid resincomposition is preferably from 5 to 9900 parts by weight, still morepreferably from 20 to 2000 parts by weight, and particularly preferablyfrom 25 to 1000 parts by weight for 100 parts by weight of thecomposition (crosslinkable particles (A) and compound (B) in total). Ifthe amount is less than 5 parts by weight, appearance of the film may beimpaired. If the amount exceeds 9900 parts by weight, the thickness ofthe film may be insufficient.

4. Polymerization Initiator (D)

In addition to the crosslinkable particles (A), the compound (B), andthe organic solvent (C), the polymerization initiator (D) may optionallybe added to the curable liquid resin composition of the presentinvention. A method of curing the composition of the present inventionincluding the use of the polymerization initiator (D) is describedbelow.

The composition of the present invention is cured by application of heatand/or radiation. In the case of curing the composition by applicationof heat, an electric heater, infrared ray lamp, hot blast, or the likemay be used as a heat source. In the case of curing the composition byapplication of radiation, there are no specific limitations to thesource of radiation insofar as the composition can be cured in a shortperiod of time after application. As an infrared ray source, a lamp,resistance heating plate, laser, and the like can be given. As a visibleray source, sunlight, a lamp, fluorescent lamp, laser, and the like canbe given. As a ultraviolet ray source, a mercury lamp, halide lamp,laser, and the like can be given. As a electron beam source, a system ofutilizing thermoelectrons produced by a commercially available tungstenfilament, a cold cathode method generating electron beams by passing ahigh voltage pulse through a metal, and a secondary electron methodwhich utilizes secondary electrons produced by collision of ionizedgaseous molecules and a metal electrode can be given. As a source ofα-rays, β-rays, and γ-rays, fissionable substances such as Co⁶⁰ can begiven. As the source of γ-rays, a vacuum tube in which acceleratedelectrons are allowed to collide with an anode or the like may beutilized. The radiation may be used either individually or incombination of two or more. One or more types of radiation may beirradiated at specific intervals of time.

The polymerization initiator (D) may be added to the composition of thepresent invention in order to decrease the curing time. As thepolymerization initiator (D), conventional compounds which produceactive radicals by heat or irradiation can be given.

In the present invention, it is preferable to use (D1) a photoinitiatoras the polymerization initiator (D). Use of a photoinitiator (D1)including at least one of an arylketone having a 1-hydroxycyclohexylgroup and an arylketone having an N-morpholino group is particularlypreferable. If only the arylketone having a 1-hydroxycyclohexyl group isadded, a cured product with a small degree of coloration can be formedin a short period of time. If only the arylketone having an N-morpholinogroup is added, a cured product with high surface hardness can be formedin a short period of time. Combined use of these compounds enables acured product with a small degree of coloration and high surfacehardness to be formed in a short period of time.

There are no specific limitations to the arylketone having a1-hydroxycyclohexyl group. As examples of the arylketone having a1-hydroxycyclohexyl group, 1-hydroxycyclohexyl phenyl ketone,1-hydroxycyclohexyl isopropylphenyl ketone, 1-hydroxycyclohexyldodecylphenyl ketone, and the like can be given. There are no specificlimitations to the arylketone having an N-morpholino group used in thepresent invention. As examples of the arylketone having an N-morpholinogroup, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1,2-methyl-1-[4-(methoxy)phenyl]-2-morpholinopropanone-1,2-methyl-1-[4-(2-hydroxyethoxy)phenyl-2-morpholinopropanone-1,2-methyl-1-[4-(dimethylamino)phenyl-2-morpholinopropanone-1,2-methyl-1-[4-(diphenylamino)phenyl]-2-morpholinopropanone-1,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,3,6-bis(2-methyl-2-morpholinopropionyl)-9-N-octylcarbazole, and the likecan be given. The photoinitiator (D1) may be used either individually orin combination of two or more. In order to increase the curing speed andhardness of the cured product both in the surface area and inside theproduct, combined use of the arylketone having a 1-hydroxycyclohexylgroup and the arylketone having an N-morpholino group is preferable.

As commercially available products of the photoinitiator (D1), Irgacure184, 907 (manufactured by Ciba Specialty Chemicals Co., Ltd.), and thelike can be given.

The amount of the photoinitiator (D1) optionally used in the compositionof the present invention is preferably from 0.01 to 20 wt %, and stillmore preferably from 0.1 to 10 wt % for 100 wt % of the composition(crosslinkable particles (A) and compound (B) in total). If the amountis less than 0.01 part by weight, hardness of the cured product may beinsufficient. If the amount exceeds 20 parts by weight, the inside(inner layer) of the cured product may remain uncured.

In the case of using the arylketone having a 1-hydroxycyclohexyl groupand the arylketone having an N-morpholino group in combination, theratio by weight of the arylketone having a 1-hydroxycyclohexyl group tothe arylketone having an N-morpholino group is preferably from 10:90 to90:10, and still more preferably from 40:60 to 80:20.

5. Other Components

Various types of components such as photosensitizers, oxide particlesother than the crosslinkable particles (A), and additives may optionallybe added to the composition of the present invention. Examples of thesecomponents are given below.

(1) Sensitizer

As examples of sensitizers, triethylamine, diethylamine,N-methyldiethanoleamine, ethanolamine, 4-dimethylaminobenzoic acid,methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl4-dimethylaminobenzoate, and the like can be given. As commerciallyavailable products of sensitizers, KAYACURE DMBI, EPA (manufactured byNippon Kayaku Co., Ltd.), and the like can be given.

(2) Oxide Particles Other Than Crosslinkable Particles (A)

As examples of oxide particles other than the crosslinkable particles(A), oxide particles which are not bonded to the specific organiccompound and the like can be given.

(3) Additive

As examples of additives, antioxidants, UV absorbers, light stabilizers,silane coupling agents, aging preventives, thermal polymerizationinhibitors, coloring agents, leveling agents, surfactants,preservatives, plasticizers, lubricants, inorganic fillers, organicfillers, wettability improvers, coating surface improvers, and the likecan be given.

As commercially available products of antioxidants, Irganox 1010, 1035,1076, 1222 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and thelike can be given. As commercially available products of UV absorbers,Tinuvin P, 234, 320, 326, 327, 328, 213, 400 (manufactured by CibaSpecialty Chemicals Co., Ltd.), Sumisorb 110, 130, 140, 220, 250, 300,320, 340, 350, 400 (manufactured by Sumitomo Chemical Industries Co.,Ltd.), and the like can be given. As commercially available products oflight stabilizers, Tinuvin 292, 144, 622LD (manufactured by CibaSpecialty Chemicals Co., Ltd.), Sanol LS 770, 765, 292, 2626, 1114, 744(manufactured by Sankyo Kasei Co., Ltd.), and the like can be given. Asexamples of silane coupling agents, γ-aminopropyltriethoxysilane,γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,commercially available products such as SH6062, SZ6030 (manufactured byToray-Dow Corning Silicone Co., Ltd.), KBE 903, KBM803 (manufactured byShin-Etsu Silicone Co., Ltd.), and the like can be given.

As examples of aging preventives, Antigen W, S, P, 3C, 6C, RD-G, FR, AW(manufactured by Sumitomo Chemical Co., Ltd.), and the like can begiven.

(4) Other Additives

As examples of other additives, polymers and oligomers such as epoxyresins, polymerizable compounds such as urethane (meth)acrylate, vinylether, propenyl ether, and maleic acid derivatives, polyamide,polyimide, polyamideimide, polyurethane, polybutadiene, chloroprene,polyether, polyester, pentadiene derivatives, styrene/butadiene/styreneblock copolymer, styrene/ethylene/butene/styrene block copolymer,styrene/isoprene/styrene block copolymer, petroleum resins, xyleneresin, ketone resin, fluorine-containing oligomer, silicone oligomer,and polysulfide oligomer, and the like can be given.

The curable liquid resin composition of the present invention issuitable as a coating material. As examples of substrates to which thecomposition is applied, plastics (polycarbonate, polymethacrylate,polystyrene, polyester, polyolefin, epoxy, melamine, triacetylcellulose, ABS resin, AS resin, norbornene resin, etc.), metals, wood,paper, glass, slates, and the like can be given. The substrate may be inthe shape of a plate, film, or three-dimensional formed product. As acoating method, conventional coating methods such as dip coating, spraycoating, flow coating, shower coating, roll coating, spin coating, andbrush coating may be employed. The thickness of the film after dryingand curing is usually from 0.1 to 400 μm, and preferably from 1 to 200μm.

The curable liquid resin composition of the present invention may bediluted with a solvent in order to adjust the thickness of the film. Inthe case where the curable liquid resin composition is used as a coatingmaterial, viscosity of the composition is usually from 0.1 to 50,000mPa.s/25° C., and preferably from 0.5 to 10,000 mPa.s/25° C.

A cured product is obtained by applying the curable liquid resincomposition of the present invention to various substrates such as aplastic substrate and curing the composition. Specifically, the curedproduct is obtained as a coated formed product by applying thecomposition to the substrate, drying volatile components at atemperature preferably from 20 to 200° C., and curing the composition byapplication of heat and/or radiation. Curing by application of heat ispreferably performed at 40–150° C. for 10 seconds to 24 hours. Asradiation, use of ultraviolet rays or electron beams is preferable. Thedose of ultraviolet rays is preferably from 0.01–10 J/cm², and stillmore preferably from 0.1 to 2 J/cm². Preferable irradiation conditionsfor electron beams are at an applied voltage of 10–300 KV, an electrondensity of 0.02–0.30 mA/cm² and a dose of 1–10 Mrad.

The cured product of the curable liquid resin composition of the presentinvention excels in hardness, scratch resistance, adhesion,transparency, and appearance of the film. Therefore, the cured productis suitable for use as a protective coating material to preventscratches or stains on plastic optical parts, optical disks such as a CDand DVD, touch panels, film-type liquid crystal elements, plasticcontainers, or flooring materials, wall materials, and artificialmarbles which are used for architectural interior finish; an adhesiveand a sealing material for various substrates; vehicles for printingink; and the like. The cured product is particularly suitably used forvarious plastic films for optics such as optical disks such as CD andDVD, liquid crystal elements, and the surface of a PDP, for which ascratch prevention protective coating excelling in transparency isdemanded.

EXAMPLES

The present invention is described below in more detail by examples.However, the present invention is not limited to the examples. In theexamples, “part” and “%” respectively refer to “part by weight” and “wt%” unless otherwise indicated.

In the present invention, “solid content”refers to the content ofcomponents after removing volatile components such as a solvent from thecomposition. Specifically, the solid content refers to the content of aresidue (nonvolatile components) obtained by drying the composition on ahot plate at 120° C. for one hour.

Synthesis of Organic Compound (A2)

Synthesis Example 1

20.6 parts of isophorone diisocyanate was added dropwise to a solutionof 7.8 parts of mercaptopropyltrimethoxysilane and 0.2 part ofdibutyltin dilaurate while stirring at 50° C. for one hour in dry air.The mixture was stirred at 60° C. for three hours. After the addition of71.4 parts of pentaerythritol triacylate dropwise to the mixture at 30°C. for one hour, the mixture was stirred at 60° C. for three hours toobtain an organic compound (A2–1). In an infrared absorption spectrum ofthe product, the absorption peak at 2550 kayser characteristic to amercapto group and the absorption peak at 2260 kayser characteristic toan isocyanate group in the raw material disappeared, and the absorptionpeak at 1660 kayser characteristic to a [—O—C(═O)—NH—] group and a[—S—C(═O)—NH—] group and the absorption peak at 1720 kaysercharacteristic to an acryloyl group appeared. This indicates that anorganic compound having an acryloyl group, [—O—C(═O)—NH—] group, and[—S—C(═O)—NH—] group as polymerizable unsaturated groups was produced.

Preparation of Crosslinkable Particles (A)

Preparation Example 1

A mixture of 8.7 parts of the organic compound (A2-1) synthesized inSynthesis Example 1, 91.3 parts of methyl ethyl ketone silica sol(MEK-ST, manufactured by Nissan Chemical Industries, Ltd., numberaverage particle diameter: 0.022 μm, silica concentration: 30%), 0.2part of isopropanol, and 0.1 part of ion exchanged water was stirred at80° C. for three hours in a nitrogen stream. After the addition of 1.4parts of methyl orthoformate, the mixture was stirred at 80° C. for onehour to obtain a colorless transparent dispersion liquid ofcrosslinkable particles (A-1). 2 g of the dispersion liquid was weighedon an aluminum dish and dried at 120° C. for one hour on a hot plate.The solid content determined by weighing the dried product was 35%.

Preparation Example 2

A mixture of 8.2 parts of the organic compound (A2-1) synthesized inSynthesis Example 1, 91.8 parts of methyl ethyl ketone zirconia sol(number average particle diameter: 0.01 μm, zirconia concentration:30%), and 0.1 part of ion-exchanged water was stirred at 60° C. forthree hours. After the addition of 1.3 parts of methyl orthoformate, themixture was stirred at 60° C. for one hour to obtain a dispersion liquidof crosslinkable particles (A-2). The solid content of the dispersionliquid determined in the same manner as in Preparation Example 1 was35%.

Preparation Example 3

A mixture of 8.2 parts of the organic compound (A2-1) synthesized inSynthesis Example 1, 91.8 parts of propylene glycol methyl ether acetatezirconia sol (number average particle diameter: 0.01 μm, zirconiaconcentration: 30%), and 0.1 part of ion exchanged water was stirred at60° C. for three hours. After the addition of 1.3 parts of methylorthoformate, the mixture was stirred at 60° C. for one hour to obtain adispersion liquid of crosslinkable particles (A-3). The solid content ofthe dispersion liquid determined in the same manner as in PreparationExample 1 was 35%.

The data for Preparation Examples 1 to 3 in which the crosslinkableparticles (A-1) to (A-3) were prepared is shown in Table 1.

TABLE 1 Preparation Example 1 2 3 Crosslinkable particles A-1 A-2 A-3Organic compound A2-1 8.7 8.2 8.2 Oxide particle sol A1-1 91.3 A1-2 91.8A1-3 91.8 Ion exchanged water 0.1 0.1 0.1 Isopropanol 0.2 — — Methylorthoformate 1.4 1.3 1.3 Solid content (%) 35 35 35 Content of oxideparticles 79 77 77 in raw materialsExplanation of Symbols in Table 1:

A1-1: Methyl ethyl ketone silica sol (oxide concentration: 30%)

A1-2: Methyl ethyl ketone zirconia sol (oxide concentration: 30%)

A1-3: Propylene glycol ethyl ether acetate zirconia sol (oxideconcentration: 30%)

Preparation of Composition

Examples 1 to 4 and Comparative Examples 1 to 3 illustrate preparationexamples of the curable liquid resin composition of the presentinvention. The weight ratio of each component is shown in Table 2.

Example 1

140 parts of the dispersion liquid prepared in Preparation Example 1(content of crosslinkable particles (A-1): 49 parts, dispersion medium:methyl ethyl ketone), 46 parts of dipentaerythritol hexaacrylate, and100 parts of propylene glycol monomethyl ether were mixed in a containershaded from ultraviolet rays in a dry air stream. The mixture wasconcentrated under reduced pressure using a rotary evaporator until theamount of liquid was 195 parts. After the addition of 3 parts of1-hydroxycyclohexyl phenyl ketone and 2 parts of2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropanone-1, the mixturewas stirred at 50° C. for one hour to obtain 200 parts of a homogeneouscurable liquid resin composition solution. 2 g of the composition wasweighed on an aluminum dish and dried at 120° C. for one hour on a hotplate. The solid content determined by weighing the dried product was50%. Therefore, the solvent was contained in an amount of 100 parts. Thesolvent was determined by using gas chromatography. As a result,propylene glycol monomethyl ether and methyl ethyl ketone were presentat a weight ratio of 90:10. The amount of propylene glycol monomethylether and methyl ethyl ketone in the composition calculated from theresults was 90 parts by weight and 10 parts by weight, respectively.

Example 2

229 parts of the dispersion liquid prepared in Preparation Example 2(content of crosslinkable particles (A-2): 80 parts, dispersion medium:methyl ethyl ketone), 18 parts of pentaerythritol tetraacrylate, and 96parts of ethylene glycol monobutyl ether were mixed in a containershaded from ultraviolet rays in a dry air stream. The mixture wasconcentrated under reduced pressure using a rotary evaporator until theamount of liquid was 194 parts. After the addition of 1 part of1-hydroxycyclohexyl phenyl ketone and 1 part of2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropanone-1, the mixturewas stirred at 50° C. for one hour to obtain a homogeneous compositionsolution. The solid content of the composition and the solvent and theweight ratio of the solvent were determined in the same manner as inExample 1. As a result, the solid content was 51% and the solvent wascontained in an amount of 96 parts. The solvent was determined byanalysis in the same manner as in Example 1. As a result, ethyleneglycol monobutyl ether and methyl ethyl ketone were present at a weightratio of 95:5. The amount of ethylene glycol monobutyl ether and methylethyl ketone in the composition calculated from the results was 91 partsby weight and 5 parts by weight, respectively.

Example 3

A composition of the present invention was prepared in the same manneras in Example 2 except for using propylene glycol monopropyl etherinstead of ethylene glycol monobutyl ether. The solid content of thecomposition and the solvent and the weight ratio of the solvent weredetermined in the same manner as in Example 1. As a result, the solidcontent was 51% and the solvent was contained in an amount of 96 parts.The solvent was determined by analysis in the same manner as inExample 1. As a result, propylene glycol monopropyl ether and methylethyl ketone were present at a weight ratio of 95:5. The amount ofpropylene glycol monopropyl ether and methyl ethyl ketone in thecomposition calculated from the results was 91 parts by weight and 5parts by weight, respectively.

Example 4

229 parts of the dispersion liquid prepared in Preparation Example 3(content of crosslinkable particles (A-3): 80 parts, dispersion medium:propylene glycol monomethyl ether acetate) and 18 parts ofpentaerythritol tetraacrylate were mixed in a container shaded fromultraviolet rays in a dry air stream. The mixture was concentrated underreduced pressure using a rotary evaporator until the amount of liquidwas 194 parts. After the addition of 1 part of 1-hydroxycyclohexylphenyl ketone and 1 part of2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropanone-1, the mixturewas stirred at 50° C. for one hour to obtain a homogeneous compositionsolution of the present invention. The solid content of the compositionand the solvent and the weight ratio of the solvent were determined inthe same manner as in Example 1. As a result, the solid content was 51%and the solvent was contained in an amount of 96 parts. The solventcontained only propylene glycol methyl ether acetate.

Comparative Example 1

A curable liquid resin composition was prepared in the same manner as inExample 1 except for using toluene as an organic solvent instead ofpropylene glycol monomethyl ether. The solid content of the compositionand the solvent and the weight ratio of the solvent were determined inthe same manner as in Example 1. As a result, the solid content was 50%and the solvent was contained in an amount of 100 parts. The solvent wasdetermined by analysis in the same manner as in Example 1. As a result,toluene and methyl ethyl ketone were present at a weight ratio of 90:10.The amount of toluene and methyl ethyl ketone in the compositioncalculated from the results was 90 parts by weight and 10 parts byweight, respectively.

Comparative Example 2

A curable liquid resin composition was prepared in the same manner as inExample 2 except for using 2-octanone as an organic solvent instead ofethylene glycol monobutyl ether. The solid content of the compositionand the solvent and the weight ratio of the solvent were determined inthe same manner as in Example 1. As a result, the solid content was 51%and the solvent was contained in an amount of 96 parts. The solvent wasdetermined by analysis in the same manner as in Example 1. As a result,methyl ethyl ketone and 2-octanone were present at a weight ratio of5:95. The amount of methyl ethyl ketone and 2-octanone in thecomposition calculated from the results was 5 parts by weight and 91parts by weight, respectively.

Comparative Example 3

A curable liquid resin composition was prepared in the same manner as inExample 2 except for using cyclohexanone as an organic solvent insteadof ethylene glycol monobutyl ether. The solid content of the compositionand the solvent and the weight ratio of the solvent were determined inthe same manner as in Example 1. As a result, the solid content was 51%and the solvent was contained in an amount of 96 parts. The solvent wasdetermined by analysis in the same manner as in Example 1. As a result,methyl ethyl ketone and cyclohexanone were present at a weight ratio of5:95. The amount of methyl ethyl ketone and cyclohexanone in thecomposition calculated from the results was 5 parts by weight and 91parts by weight, respectively.

Evaluation of Cured Product

In order to demonstrate the effects of the composition of the presentinvention, a cured product obtained by applying the composition, dryingthe applied composition, and irradiating the dried product wasevaluated. The evaluation methods are described below. The evaluationresults are shown in Table 2.

1. Conditions for Application, Drying, and Curing

In Examples 1 to 4 and Comparative Examples 1 to 3 shown in Table 2, thecomposition was applied to a substrate using a bar coater so that thethickness was 10 μm after drying, dried at 80° C. for three minutes in ahot blast oven, irradiated at a dose of 1 J/cm² using a conveyer-typemercury lamp, and stored at 25° C. for 24 hours before the evaluation.The application conditions for a wind ripple pattern test and a streaktest are described later.

2. Substrate

A glass plate was used in a pencil hardness test. Apolyethyleneterephthalate (PET) film with a thickness of 188 μm was usedin evaluation of steel wool scratch resistance, adhesion, the windripple test, and the streak test.

3. Evaluation Method

Pencil Hardness:

A film cured on a glass substrate was evaluated according to JIS K5400.

Adhesion (%):

According to a cellophane tape cross-cut peeling test described in JISK5400, adhesion was evaluated by the percentage of the number of 1×1 mmsquares remaining among 100 squares.

Steel Wool (SW) Scratch Resistance:

A Gakushin-type abrasion resistance tester (manufactured by TesterSangyo Co., Ltd.) was reciprocated on a film 30 times using #0000 steelwool to which a load of 500 g was applied. SW scratch resistance wasevaluated by observing scratch conditions on the surface of the filmwith the naked eye. A case where no scratch was observed was evaluatedas “Good”, a case where 1–10 scratches were observed was evaluated as“Fair”, and a case where more than 10 scratches were observed wasevaluated as “Bad”.

Transparency:

Transparency was evaluated by naked eye observation. Transparency wasevaluated as “Good” or “Bad”.

Film Uniformity Test:

4 cc of the curable liquid resin composition was applied dropwise to asilicon wafer (six inches) while rotating the wafer at 50 rpm. Thecomposition was applied at 700 rpm for 20 seconds and dried at 80° C.for three minutes in a hot blast oven. The dried product was irradiatedat a dose of 1 J/cm² using a conveyer-type mercury lamp to obtain acured film. The degree of unevenness of the film was observed with thenaked eye. A case where reflection of light on the surface of the filmwas uniform and no abnormalities were observed in the film was evaluatedas “Good”, and a case where reflection of light on the surface of thefilm was nonuniform and an interference pattern was observed or a casewhere one or more foreign materials were present on the film orabnormalities such as uneven coating or crawling were observed wasevaluated as “Bad”.

Wind Ripple Pattern Test:

The curable liquid resin composition was applied to a PET film using abar coater so that the thickness after drying was 10 μm. A current ofair was blown against the surface of the applied composition for twominutes using a cooling fan (velocity: 5 m/sec.). After drying thecomposition at 80° C. for three minutes in a hot blast oven, thecomposition was irradiated at a dose of 1 J/cm² using a conveyer-typemercury lamp to obtain a cured film. The degree of unevenness of thefilm was observed with the naked eye. A case where reflection of lighton the surface of the film was uniform and no abnormalities wereobserved in the film was evaluated as “Good”, and a case wherereflection of light on the surface of the film was nonuniform or a casewhere one or more foreign materials were present on the film orabnormalities such as uneven coating or crawling were observed wasevaluated as “Bad”.

Streak Test:

1 ml of the curable liquid resin composition was applied dropwise to aPET film at a width of 10 cm. After allowing to stand at roomtemperature for two minutes, the composition was applied using a barcoater so that the thickness after drying was 10 pm and dried at 80° C.for three minutes in a hot blast oven. The dried product was irradiatedat a dose of 1 J/cm² using a conveyer-type mercury lamp to obtain acured film. The degree of unevenness of the film were observed with thenaked eye. A case where no traces of the bar coater was observed on thefilm was evaluated as “Good”, a case where the trace of the bar coaterwas 1 cm to 3 cm or less was evaluated as “Fair”, and a case where thetrace of the bar coater was more than 3 cm was evaluated as “Bad”.

TABLE 2 Comparative Example Example 1 2 3 4 1 2 3 Crosslinkableparticles (A) A-1 49 49 A-2 80 80 80 80 A-3 80 Acrylate M1 46 46 M2 1818 18 18 18 Photoinitiator R1 3 1 1 1 3 1 1 R2 2 1 1 1 2 1 1 Organicsolvent (boiling point, ° C.) Methyl ethyl ketone 10 5 5 10 5 5 (80)PGMME (120) 90 EGMBE (170) 91 PGMPE (150) 91 PGMEA (146) 96 Toluene(111) 90 2-Octanone (173) 91 Cyclohexanone (156) 91 Total 200 196 196196 200 196 196 Solid content (%) 50 51 51 51 50 51 51 Properties ofcured product Pencil hardness 8H 8H 8H 8H 8H 8H 8H Adhesion (%) 100 100100 100 100 100 100 SW scratch resistance Good Good Good Good Good GoodGood Transparency Good Good Good Good Good Good Good Applicability Filmuniformity Good Good Good Good Bad Bad Bad Wind ripple Good Good GoodGood Bad Bad Fair Streak Good Good Good Good Fair Fair FairExplanation of Symbols in Table 2:A-1, A-2, A-3: value of crosslinkable particles (A) is solid content(part by weight) of crosslinkable particles in dispersion liquid

-   M1: Dipentaerythritol hexaacrylate-   M2: Pentaerythritol tetraacrylate-   R1: 1-Hydroxycyclohexyl phenyl ketone-   R2: 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1-   PGMME: Propylene glycol monomethyl ether-   EGMBE: Ethylene glycol monobutyl ether-   PGMPE: Propylene glycol monopropyl ether-   PGMEA: Propylene glycol methyl ether acetate

The unit for the values of each component in Table 2 is part by weight.

As is clear from data in Table 2, pencil hardness, adhesion, steel woolscratch resistance, and transparency of the cured products of thecurable liquid resin compositions were good. Applicability of thecurable liquid resin compositions of the present invention in Examples 1to 4 was evaluated as “Good” in the film uniformity test, wind ripplepattern test, and streak test. However, applicability of thecompositions in Comparative Examples 1 to 3 were evaluated as “Bad” or“Fair” in these tests.

Effect of the Invention

As described above, the present invention can provide a curable liquidresin composition having excellent applicability and capable ofproducing a film excelling in hardness, scratch resistance, adhesion,transparency, and appearance of the surface of the film.

1. A curable liquid resin composition comprising: (A) crosslinkableparticles prepared by bonding oxide particles of at least one elementselected from the group consisting of silicon, aluminum, zirconium,titanium, zinc, germanium, indium, tin, antimony, and cerium to aspecific organic compound which comprises a polymerizable unsaturatedgroup and a group shown by the following formula (1), (B) a compoundhaving two or more polymerizable unsaturated groups in the molecule, and(C) at least one organic solvent selected from compounds shown by thefollowing formula (2);—X—C(═Y)—NH—  (1) wherein X represents NH, O (oxygen atom), or S (sulfuratom), and Y represents O or S;R²—(O—R¹)_(n)—O—R³  (2) wherein R¹ represents a divalent organic groupselected from —CH₂CH2—,—CH₂CH₂CH₂—, and —CH (CH₃) CH₂—, R² and R³represent a hydrogen atom or a monovalent organic group selected from analkyl group having 1–4 carbon atoms and CH₃CH—, and n is 1 or 2, withthe proviso that when n=1 and R³ has 1 carbon atom, R² is not H.
 2. Thecurable liquid resin composition according to claim 1, wherein thespecific organic compound comprises a group shown by —O—C(═O)—NH— and atleast one of the groups shown by —O—C(═S)—NH— and —S—C(═O)—NH—.
 3. Thecurable liquid resin composition according to claim 1, wherein thespecific organic compound is a compound having a silanol group or agroup which forms a silanol group by hydrolysis.
 4. The curable liquidresin composition according to claim 1, further comprising (D) apolymerization initiator in addition to the components (A), (B), and(C).
 5. The curable liquid resin composition according to claim 4,wherein the polymerization initiator (D) is a photoinitiator whichcomprises at least either an arylketone having a 1 -hydroxycyclohexylgroup or an arylketone having an N-morpholino group.